On Saturday, 5 October 2019 12:55, Pierre Neidhardt <m...@ambrevar.xyz> wrote:
> Hi! > > While the documentation refers to profiles and manifests, it does not tell > much > of the use cases and the practical benefits. > > For users coming from non-functional package managers, it's not really obvious > why we would need profiles. > > Regarding manifest, I suppose some people might find them annoying to use > because updating/adding just 1 program means rebuilding the whole profile, > which > after a Guix pull can be somewhat lengthy. > > So what about writing a blog article / cookbook chapter to explain why > profiles and manifests are truly awesome indeed? (Unless this has > already been done and I missed it?) > > A quick 'n' dirty outline: > > A manifest can be slow to install if it's too big. But Guix supports profile, > which are perfect to break down manifests into multiple sets of semantically > connected packages. > > Example profiles: > > - Emacs. > - TeXlive (this one can be really useful when you need to install just one > package for the next document you've received over email). > > - Your favourite programming language libraries. > - The dependencies of a project you are working on > - Games :p > > We can create a manifest per profile and install them this way: > > guix package --manifest=/path/to/guix-dev-manifest.scm > --profile=$HOME/.guix-extra-profiles/dev/dev > > Placing all your profiles in a single folder, with each profile getting > its own > subfolder is somewhat cleaner, plus it's obvious to "loop over profiles" > from > any programming language (e.g. a shell script) by > simply looping over the sub-directories of .guix-extra-profiles. > > Note that it's also possible to loop over the output of `guix package > --list-profiles` although you'll probably have to filter out > `~/.config/guix/current`. > > To "enable" all profiles on login, add this to your .bash_profile (or > .profile > if you don't use bash): > > #+begin_src sh > for i in ~/.guix-extra-profiles/*; do > profile=$i/$(basename "$i") > if [ -f "$profile"/etc/profile ]; then > GUIX_PROFILE="$profile" ; . "$profile"/etc/profile > fi > unset profile > done > #+end_src > > I like to keep the default ~/.guix-profile manifest-less for trash-away > packages > that I would just use for a couple of days. > This way it's easy to just run > > guix install FOO > guix upgrade BAR > > and I don't have to specify the profile. > > Other benefits of manifests: > > - No need to generate or maintain a manifest from an ad-hoc profile. > - "guix package -u" will always suggest to update some packages of those > have > propagated inputs. Guix manifests avoid this problem. > > - "guix package -u [packages...]" may report conflicts which are annoying to > resolve manually. Manifests avoid this problem altogether. > > Other benefits of multiple profiles > > - It's easy to toggle a specific profile on/off. > - When a profile is off, it's easy to enable it for an individual shell > without > "polluting" the rest of the user session: > > #+begin_src sh > GUIX_PROFILE="$profile" ; . "$profile"/etc/profile > #+end_src > > Happy to hear about your feedback! > > Cheers! > > -- > Pierre Neidhardt > https://ambrevar.xyz/ > What is the advantage of having different profiles to just defining different top-level packages propagating all programs and libraries one needs and placing them in a custom channel? My feeling is, defining a package is cleaner than manifests+profiles, because it does not involve creating yet another shell program that needs to be sourced.
